Artifacts are printed pixel patterns which appear objectionable for a given solid color area. More specifically, artifacts appear as low frequency patterns in the color level. These patterns make the color level appear as a distinct combination of two or more colors and patterns rather than a uniform single color level. Conversely, artifact-free color levels have fine dot patterns which are difficult to observe.
Artifacts arise from the fact that most display devices such as, for example, printers, do not have enough available color levels to render all the color levels desired for a high quality image. Accordingly, such display devices must employ some type of halftoning to render all of the required color levels. Consequently, some of the halftone patterns employed by such devices for the required color levels include artifacts. The result is often a rendered image which has one or more areas appearing un-natural or "grainy" rather than smooth.